(Adds Boeing comment, details of United's fleet plans)
By Jeffrey Dastin
April 23 (Reuters) - United Airlines said Thursday that it has swapped 10 orders of Boeing Co 787 Dreamliners for 10 larger 777-300ER jets, marking a victory for the plane manufacturer as it seeks to sell out the 777 planes before their production ends.
The news follows months of speculation that Chicago-based United Continental Holdings Inc would make the swap, which allows it to move aircraft on to different routes to better fit customer demand.
The carrier also said it is in final negotiations on the lease of 10 to 20 used narrow-body aircraft for delivery over the next few years. It said it plans to retire 130 of its more than 200 50-seat planes by the end of 2015 as part of its fleet reorganization.
For Boeing, the deal signals steady demand for its wide-body 777 aircraft before it switches to production of the new 777X model later this decade. Boeing said Wednesday that its 777 production line is sold out for 2016 and half sold out in 2017, with sales extending into 2018.
The additions from United were part of the 25 firm orders and commitments for 777s that Boeing has won this year, just short of half of its target, spokesman Doug Alder confirmed in an email.
"We always work with our customers on their evolving fleet needs and we're pleased United chose the 777-300ER," he said.
Analysts have expressed concern that Boeing might have to cut prices to shore up any 777 production gap.
United said it will accept delivery of the 777-300ER aircraft beginning in 2016, adding that the aircraft "will provide attractive upgauge and range opportunities to the company at competitive economics".
United added it intends to extend the life of all 21 of its Boeing 767-300ER aircraft and switch some of its Boeing 757-200 aircraft from transatlantic to U.S. and Latin American routes.
(Reporting By Jeffrey Dastin in New York; Editing by Chizu Nomiyama; and Peter Galloway)